Why bother with argv[0]?
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Why bother with argv[0]?
1–10 of 277 posts
Re: Why bother with argv[0]?
#2Wait until he finds out about busybox!
Also claiming that the windows API to call a new process is good… wow… I guess he's never had to pass a filename with quotes and spaces in its name. The API expects you to do the escaping yourself. Yes it needs to be escaped, because it's all one single string.
Re: Why bother with argv[0]?
#3[deleted]
Re: Why bother with argv[0]?
#4It is sometimes used to allow one binary to be the symlink target of hundreds of commands.
Android does this for most common shell commands. Toybox and busybox are examples of such implementations.
Re: Why bother with argv[0]?
#5This is how busybox works in 'shim' mode. I am not however concerned with the security argument here, if you have the ability to run code you have the ability to do n to the power of x insidious things, and arg[0] abuse is just one of dozens, (hundreds?) of vectors or useful building blocks in an attack. if we are suddenly giving a shit about security on nixens, we should be looking at deeper SELinux rollouts (ease of use for sysadmins and maintainers so we never see permissive mode instead of just applying the difficult to remember command that will patch your policy settings. We need root capabilities to continue to be separated in the kernel access control scheme and probably we need to start using namespaces much more liberally like projects like silverblue/bluefin which reimplement entire os stack as a series of containers. Stronger container foundations and ease of use for existing security mechanisms will take us much further than worrying about ANYTHING else in the ABI which by the way will never change as long as linus is alive, and he will live on forever as an LLM most likely with the amount of mailing list posts he has made over the years.
Re: Why bother with argv[0]?
#6Microsoft defender using broken by design detection rules? One could almost think it is an anti virus program.
Re: Why bother with argv[0]?
#7> Today however, disk space is no longer considered an issue
On desktop machines, perhaps, but this is certainly not true on all platforms Linux runs on.
Re: Why bother with argv[0]?
#8It is sometimes used to allow one binary to be the symlink target of hundreds of commands. Android does this for most common shell commands. Toybox and busybox are examples of such implementations. https://github.com/landley/toybox https://en.m.wikipedia.org/wiki/BusyBox
Also if you want a program to call itself, which is sometimes useful, this way lets you actually call the same program, rather than assuming the name and path.
Re: Why bother with argv[0]?
#9This is why we can't have nice things. Security footguns everywhere!
I'm fascinated by the intersection of argv[0], and the execve behavior of replacing the calling program with the called one.
Aside from that, I quite like argv[0], for a much more limited set of reasons than considered in this interesting and comprehensive article. I like the ability to "retitle" a process to put a useful, descriptive, or branded name in there to be seen by ps, et al.
NodeJS also exposes this feature, but not quite as you might expect. Whereas in C, setting argv[0] from within the program's execution context will alter what is observed by ps, in NodeJS process.argv is just a descriptive getter. Setting its slots has no effect outside of its context.
But this is where process.title steps in. Setting process.title allows you to (in an OS-dependent way) change the name reported in ps and similar tools.
Read more here: https://nodejs.org/api/process.html#processtitle
Please don't kill argv[0], its lease hath all too short a date
Re: Why bother with argv[0]?
#10I wish amateurs would stop propagating the false idea that disk space and memory are cheap and not a problem.